src/share/vm/utilities/ostream.hpp

*** 25,34 ****
--- 25,35 ----
  #ifndef SHARE_VM_UTILITIES_OSTREAM_HPP
  #define SHARE_VM_UTILITIES_OSTREAM_HPP
  
  #include "memory/allocation.hpp"
  #include "runtime/timer.hpp"
+ #include "runtime/task.hpp"
  
  class GCId;
  DEBUG_ONLY(class ResourceMark;)
  
  // Output streams for printing
*** 233,262 ****
--- 234,291 ----
    int fd() const { return _fd; }
    virtual void write(const char* c, size_t len);
    void flush() {};
  };
  
+ class Mutex;
+ class GCLogEvent;
+ 
  class gcLogFileStream : public fileStream {
   protected:
    const char*  _file_name;
    jlong  _bytes_written;
    uintx  _cur_file_num;             // current logfile rotation number, from 0 to NumberOfGCLogFiles-1
+  private:
+   GCLogEvent* _reader;
+   GCLogEvent* _writer;
+   Mutex* _lock;
+ 
   public:
    gcLogFileStream(const char* file_name);
    ~gcLogFileStream();
+   // write asynchronously
    virtual void write(const char* c, size_t len);
+   // really write to file system.
+   void write_blocking(const char* c, size_t len);
    virtual void rotate_log(bool force, outputStream* out = NULL);
+   void flush_log();
    void dump_loggc_header();
  
    /* If "force" sets true, force log file rotation from outside JVM */
    bool should_rotate(bool force) {
      return force ||
               ((GCLogFileSize != 0) && ((uintx)_bytes_written >= GCLogFileSize));
    }
  
  };
  
+ class GCLogFlusher: public PeriodicTask {
+   gcLogFileStream * _ostream;
+   elapsedTimer _accumulatedTime;
+ public:
+   GCLogFlusher(int interval, gcLogFileStream* ostream):PeriodicTask(interval), _ostream(ostream) {}
+ 
+   virtual void task() {
+     TraceTime t("GCLogFlusher", &_accumulatedTime, true, PrintGCLogFlushTime);
+     _ostream->flush_log();
+   }
+ 
+   elapsedTimer getAccumulatedTime() {
+     return _accumulatedTime;
+   }
+ };
+ 
  #ifndef PRODUCT
  // unit test for checking -Xloggc:<filename> parsing result
  void test_loggc_filename();
  void test_snprintf();
  #endif